Apple launched a trade-in program for iPhone users to bring in their current models for credit towards a new one, CNBC first reported.

Apple is not the first retailer to offer such a service, as Amazon, Best Buy, RadioShack, Verizon and other carriers are offering their own iPhone reuse and recycling program.

The trade-in program is just ahead of a Sept. 10 event in which the Cupertino, Calif. tech company is expected by analysts and insiders to announce the new iPhone. While that may not be its official release date, it certainly will not be too far behind the initial unveiling.

Todd Day, senior industry analyst for Frost & Sullivan, said Apple offering a competitive trade-in program would be important for keeping its customers around. The tech giant expanded upon its previous program and now offers store credit at rates competitive with other major retailers.

"If you look at Apple's overall business model, it's not just about the devices but the overall universe," he said.

If kept in good condition, a two-year-old 16 GB iPhone 4S could go for $230, which covers the typical $200 price tag for a new phone under a contract. A 16 GB iPhone 5 could return up to $390, which could put a dent in the new phone's full retail price.

Apple joins Best Buy, Verizon and Amazon as retailers who would give a customer trading in an iPhone the credit on a gift card. To encourage people to trade in their old phones with them and continue to shop with them, they also offer the highest rates. Other companies offering trade-in programs are RadioShack, NextWorth and Gazelle.

An Apple spokesperson released a statement on the trade-in program Friday.

"iPhones hold great value. So, Apple Retail Stores are launching a new program to assist customers who wish to bring in their previous-generation iPhone for reuse or recycling," the statement said. "In addition to helping support the environment, customers will be able to receive a credit for their returned phone that they can use toward the purchase of a new iPhone."